/*
 * Copyright 2017, OpenRemote Inc.
 *
 * See the CONTRIBUTORS.txt file in the distribution for a
 * full listing of individual contributors.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.openremote.model.query.filter;

import org.openremote.model.util.JSONSchemaUtil.*;

import java.util.Objects;
import java.util.function.Predicate;
import java.util.function.Supplier;

@JsonSchemaTitle("Empty value")
@JsonSchemaDescription("Predicate that matches any empty/null value; unless negated.")
public class ValueEmptyPredicate extends ValuePredicate {

    public static final String name = "value-empty";
    public boolean negate;

    public ValueEmptyPredicate negate(boolean negate) {
        this.negate = negate;
        return this;
    }

    @Override
    public Predicate<Object> asPredicate(Supplier<Long> currentMillisSupplier) {
        return obj -> negate != Objects.isNull(obj);
    }
}
